As printing technologies migrate from traditional printing methods such as lithography to digital printing, use of digital printers and associated processing of printed images and page layouts in digital printing systems has dramatically increased. While traditional printing methods may still be more cost effective for large quantities of standardized print, the cost of digital printing systems and associated media has continued to decrease, making digital printing more affordable. In addition, digital printing technology can often facilitate customized printing in a more cost-effective way that traditional high volume printing methods.
For example, one type of customized printing is known as variable-data printing (VDP) (also known as variable-information printing (VIP) or VI or variable data publishing). VDP is a form of on-demand printing in which elements such as text, graphics and images may be changed from one printed piece to the next, without stopping or slowing down the printing process and without using information from a database or external file. For example, a set of personalized letters, each with the same basic layout, can be printed with a different name and address on each letter, while retaining other common elements, such as images, text, associated drop shadows, or other common elements. Variable data printing is typically used for direct marketing, customer relationship management, advertising and invoicing on self-mailers, brochures, or postcard campaigns, but may also be used for a range of other printing applications where customization is required. An article describing VDP entitled “Speaking in Tongues: Sorting Out Variable Data Printing Languages” by Eliot Harper, incorporated by reference herein, is available at http://www.fujixerox.com.au/products/image/media/TSR-0906-Speak-Tongues-reprint.pdf. VDP printing may be implemented using a language such as Personalized Print Markup Language or PPML, which is described in an article entitled “Introduction to the Personalized Print Markup Language: The PPML Family of XML Standards, available at ppml.podi.org/component/option,com_docman/Itemid,0/task,doc_download/gid,13&Itemid=/ which explains how PPML can be used to implement VDP by caching images and reusing them.
VDP is a direct outgrowth of digital printing technology, which harnesses computer systems, digital printing devices, and specialized software to create high-quality black and white or full color documents with a look and feel comparable to conventional offset printing. Variable data printing enables the mass customization of documents via digital print technology, as opposed to the ‘mass-production’ of a single document using offset lithography. For example, instead of producing 10,000 copies of a single document to deliver a single message to 10,000 customers, variable data printing provides for printing 10,000 unique documents with customized messages for each customer.
There are two main operational modes to VDP. In one mode, the document template and the variable information are both sent to a Raster Image Processor or Raster Image Processing System (RIP) which combines the two to produce each unique document. The other mode is to combine the static and variable elements prior to printing, using specialized VDP software applications. These applications produce a print job in a programming language format, such as in PostScript or PPML, which organizes the print stream efficiently so that the static elements need only be processed once by the RIP. Consequently, digital printing systems using VDP have become more and more pervasive, while providing high quality, customizable print output on even small office and print shop printing devices. The wide availability of digital pre-print tools such as the Fusion Pro Desktop, designed and sold by the assignee of this application, allow users to generate custom VDP print jobs on a wide variety of print composition computer systems and either print them on their own printing systems or send the print job to a third party printing system to generate the printed output.
Despite the availability of these printing systems and associated software applications, processing of a digital print job at the printing apparatus is often slowed by the need to rasterize images, font effects, and other print features, just before printing, at the RIP. This has the effect of slowing down the overall print throughput and increasing printing costs. Consequently, there is a need in the art for improved systems and methods for enhancing the performance and throughput of digital printing, and in particular enhancing print job raster image processing by using pre-rasterization of print elements based on predetermined printer characteristics.